The Clinical Study Unit provides the framework and support for a diverse group of studies. These include - 1) prospective screening of individuals genetically susceptible to medullary carcinoma of the thyroid and to pheochromocytoma; 2) studies of effect of external counterpulsation on angina and coronary collateral circulation; 3) secretion of hypothalamic hormones, TRF and LRF and feedback control of these hormones; 4) effect of induced zinc deficiency on wound healing; 5) effect of hypertransfusion on course of thalasemia and sickle cell disease; 6) chemotherapy of osteogenic sarcoma; 7) pathogenesis of metabolic bone disease; 8) effects of TRF and LRF on pituitary secretion.